AN2539 Freescale Semiconductor / Motorola, AN2539 Datasheet - Page 3

• Manufacturer Part Number: AN2539
• Description: Using the MC9328MX1/MC9328MXL Single Internal 32.768 kHz Crystal to Generate System Clock and USB
• Manufacturer: Freescale Semiconductor / Motorola

4 USB Certification Results
The i.MX processor ADS can achieve USB certification using the single internal 32.768 kHz crystal input
to the MCU PLL and System PLL for generation of the system clock and the 48 MHz USB clock. As of
this publication date, overall test results pass the current requirements. The USB certification results are
provided at the end of this document. The Table 5 and Figure 1 on page 3 highlight the individual test
results regarding signal quality.
MOTOROLA
Signal eye:
Measured signaling rate: 12.0028 MHz
E Receivers: reliable operation on tier 6
Consecutive jitter range: -0.2ns to 0.3ns RMS jitter 0.2ns
Paired JK jitter range: -0.1ns to 0.2ns, RMS jitter 0.1ns
Paired KJ jitter range: -0.3ns to 0.2ns, RMS jitter 0.2ns
EOP width: 167.77ns
Maximum cycle to cycle jitter mean value
Maximum cycle to cycle jitter standard deviation
Maximum cycle to cycle jitter mean value
Maximum cycle to cycle jitter standard deviation
Table 5. Jitter Measurement Results (Signal Quality and Eye Diagram)
Table 4. Cycle to Cycle Values (MC9328MX1/MC9328MXL)
Measurement Parameter
Freescale Semiconductor, Inc.
MC9328MX1/MC9328MXL Application Note
For More Information On This Product,
MC9328MX1
MC9328MXL
Figure 1. Jitter Measurement
Go to: www.freescale.com
32,768 kHz
32,768 kHz
78.577ps
78.061ps
126.37ps
92.748ps
Signal Rate Passes
EOP Width Passes
USB Certification Results
Receivers Pass
Jitter Passes
Eye Passes
Pass/Fail
68.339ps
68.534ps
93.813ps
92.584ps
16 MHz
16 MHz
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